Angiotensin II and NGF differentially influence microtubule proteins in PC12W cells: role of the AT2 receptor.
Angiotensin AT2 receptors have been shown to play a role in cell differentiation characterized by neurite outgrowth in neuronal cells of different origin. To further investigate AT2 receptor-mediated events leading to neurite formation, we examined the effect of AT2 receptor stimulation on the microtubule components, beta-tubulin, MAP1B and MAP2, by Western blot analysis and immunofluorescence in quiescent and nerve growth factor (NGF)-differentiated PC12W cells. These proteins are involved in neurite extension and neuronal maturation. Whereas NGF (0.5, 10, and 50 ng/ml) up-regulated these proteins after 3 days of stimulation, angiotensin II (ANG II; 10(-7) M) induced a different pattern. In quiescent PC12W cells, AT2 receptor stimulation up-regulated polymerized beta-tubulin and MAP2 but down-regulated MAP1B protein levels. In PC12W cells, differentiated by NGF (0.5 ng/ml), ANG II elevated polymerized beta-tubulin and reduced MAP1B. All ANG II effects were abolished by the AT2 receptor antagonist PD123177 (10(-5) M) but not affected by the AT1 receptor antagonist losartan (10(-5) M). These results implicate a specific role of AT2 receptors in cell differentiation and nerve regeneration via regulation of the cytoskeleton.
Stroth
U
U
Department of Pharmacology, Christian-Albrechts University, Hospitalstrasse 4, D-24105 Kiel, Germany. department@pharmakologie.uni-kiel.de
Meffert
S
S
Gallinat
S
S
Unger
T
T
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D008868:Microtubule Proteins / Q000096:biosynthesis*; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D016716:PC12 Cells; D051381:Rats; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000502:physiology*; D014404:Tubulin / Q000096:biosynthesis
D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D009414:Nerve Growth Factors; D011945:Receptors, Angiotensin; D014404:Tubulin; D000804:Angiotensin II